Retinal Artery Occlusions
Retinal Consultants of Arizona Presents – Retinal Artery Occlusion Patient Education Series
A retinal artery occlusion occurs when one of the arteries in the retina is blocked (occluded) by a cholesterol plaque or clot and cannot deliver blood to the retina. This blockage causes damage to the surrounding retina due to a lack of blood flow. If the blood flow remains poor, the retinal cells can die with subsequent loss of vision. Risk factors for retinal artery occlusions include: carotid artery disease, elevated cholesterol, high blood pressure, and cardiovascular disease.
Type of retinal artery occlusions
When the major artery that supplies blood to the retina from the optic nerve is blocked, this is called a central retinal artery occlusion (CRAO). When the blockage involves a smaller artery, this is called a branch retinal artery occlusion (BRAO).
The symptoms of retinal artery occlusions can vary but include: sudden, painless loss of vision (partial or complete), peripheral vision changes, and distortion.
Your doctor can diagnose a retinal artery occlusion by looking at your retina during a dilated eye exam. Often, a plaque or clot is seen in the affected artery. Sometimes your doctor may recommend other diagnostic tests, including fluorescein angiogram and optical coherence tomography (OCT). These special tests can help to evaluate the extent of the blockage. Your doctor will probably recommend you see your family physician for a complete cardiovascular work-up to evaluate the risk factors mentioned above.
Unfortunately, there is no cure or good treatment for retinal artery occlusions. The main cause of vision loss in patients with retinal artery occlusions is due to a lack of blood flow to the retina. Your doctor may try to improve blood flow by lowering the eye pressure with a procedure called anterior chamber paracentesis. However, even by lowering the eye pressure, there is rarely an improvement in blood flow. In rare cases, abnormal blood vessels grow which can cause painful glaucoma. In these cases, laser treatment and/or injections of medicine (Avastin or Lucentis) is necessary. Some patients require surgery to control eye pressure despite using laser and injections.